Don't use handles in the Calendar event name migration
Summary:
Fixes T8209. Using handles can now cause cache fills as a side effect of T7707. Use a raw query instead.
I'll follow up on T8209 with some context and ideas for longer-term fixes.
Test Plan:
- Set event names to ''.
- Reran migration with --apply ... --trace.
- Saw migration work correctly without executing cache fills.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T8209
Differential Revision: https://secure.phabricator.com/D12858